In homeopathy prescription is done on the totality of the
characteristic symptoms, as Hahnemann said in the
Organon. Prescription on a single symptom while ignoring other
characteristic symptoms is not good homeopathy. So what is the role of
keynotes? The job of the homeopath is to find the remedy which is most
similar to the symptoms of the patient. But because of the finite
capacity of the mind, the homeopath can only consider a certain number
of symptoms and remedies when selecting the most similar remedy. The
role of keynotes is to guide the homeopath in selecting symptoms and
remedies. If a symptom is clearly and strongly expressed by the
patient and that symptom is a keynote of a remedy, that remedy
becomes a candidate to be considered when choosing the most similar
remedy. The role of the keynote is to help the homeopath to keep from
being lost in a mass of details. However, the selection is only one
step in choosing the remedy. The materia medica is always the final
authority in choosing the remedy. So how does a symptom become a
keynote of a remedy? Keynotes are based on the clinical experience of
homeopaths. When a homeopath finds that a symptom is a reliable guide
to a remedy it becomes a keynote of that remedy. Because this process
is somewhat subjective, different homeopaths will disagree on whether
a symptom is a keynote. Keynotes are a useful tool in selecting the
most similar remedy. However, knowledge of the repertory and materia
medica are equally important.

The keynotes here have been selected from Nash's Regional
Leaders. I have selected keynotes that I hope acute prescribers will
find useful.

Aconite

When little sharp foreign bodies have entered the eyes, before they
can be removed, and after removal.

Croupy cough, awaking in first sleep, particularly with children,
after dry, cold west wind.

Allium Cepa

Copious, watery, acrid discharge from the nose, and watering bland
discharge from the eyes.

Constant sneezing with profuse acrid coryza, when coming into a
warm room.

Apis mellifica

Sudden, shrill, piercing screams (awake or sleeping).

Oedematous swelling of the throat; uvula hangs down and looks like
a transparent bag filled with water.

Arnica Montana

Fear of being touched by persons coming towards him.

Bad effect even in inflammations, from mechanical injuries, falls,
bruises, and contusions.

Arsenicum Album

Very great anguish and restlessness; cannot rest anywhere, moves
from place to place; wants to go from one bed to another.

Unquenchable thirst; drinks often, but little at a time; the water
disagrees.

Belladonna

Pulse much increased in force and frequency, with throbbing of
carotid and temporal arteries.

Skin is so hot it burns the hand to touch.

Bryonia Alba

Very irritable, inclined to be angry, chilly, or a red face and
heat in the head.

The great characteristic is aggravation from motion.

Cantharis

Tenesmus of the bladder; urine scalds and burns; passed drop by
drop.

Pain in loins, kidneys and abdomen, with such pain on urination
that he could not pass a single drop without wanting to moan or
scream.